GCC -The speed king

There are no compilers that will ever approach the speed of gcc,
Especially your toy languages.

GCC is an ugly mess of a compiler. It's optimizations are bottom of the barrel (though they are slowly improving) and hte code base is completely and utterly disastrous. You will want to kill yourself the moment you deal with it.

LLVM is the future, sadly it's still using GCC as a front end, however I think it will be a much more useful platform for compiler development once it's matured a bit more. Also once it's C/C++ front end(clang) is out.